Alignment Of Cervical Spine Research Articles

Friday, September 28, 2018 10:30 AM–12:00 PM abstracts: complications of cervical spine surgery: 163. Sagittal alignment parameters associated with adjacent segment pathology after anterior cervical discectomy and fusion

BACKGROUND CONTEXT Changes in the cervical alignment from preoperative to postoperative may alter cervical spine mechanics, and increase the rate of early adjacent segment pathology. Correction and restoration of cervical sagittal alignment is crucial in achieving a successful result after an ACDF and potentially decreasing the risk of developing ASD. PURPOSE We sought to evaluate the relationship between cervical spine sagittal alignment and adjacent segment disease (ASD) following anterior cervical discectomy and fusion (ACDF) as determined by radiographic and clinical outcomes. STUDY DESIGN/SETTING Retrospective Cohort Series. PATIENT SAMPLE Patients undergoing ACDF from 2008 to 2015 who developed radiographic signs of ASD(+) were identified and compared to a matched group of ACDF patients who did not develop radiographic evidence of ASD(−) for a period of at least 1 year. Patients were excluded from analysis if they were under 18 years of age at the time of surgery, had postoperative follow up less than 12 months or had an ACDF for cervical spine fracture or infection. OUTCOME MEASURES The number or location of levels fused was recorded and radiographs were reviewed preoperatively, immediately postoperative, and at final follow up. The sagittal parameters measured included change in C2-C7 lordosis, T1 angle, levels fused, sagittal vertical axis (SVA), fusion mass lordosis, proximal and distal adjacent segment lordosis. Patient reported outcomes were obtained in the form of Neck Disability Index (NDI) scores and Visual Analog Scales (VAS) scores for the neck and arm. Radiographic diagnosis of ASD was determined by the presence of new or enlarged osteophytes, endplate sclerosis, disc space narrowing g50%, and/or increased calcification of the anterior longitudinal ligament (ALL) as presented by previous published studies. METHODS Radiographic diagnosis of ASD was determined by the presence of new or enlarged osteophytes, endplate sclerosis, disc space narrowing g50%, and/or increased calcification of the anterior longitudinal ligament (ALL) as presented by previous published studies. Baseline patient characteristics were compared using chi-squared analysis and independent sample t-tests for categorical and continuous data, respectively. Bivariate and multivariate regressions were subsequently used to compare clinical outcomes between procedure groups. Multivariate analyses controlled for differences in baseline patient characteristics. RESULTS A total of 101 ASD(+) patients were identified having underwent ACDF from 2008 to 2015 and compared to 131 ASD(−). The ASD(−) were free of ASD for a period of at least 1 year. The groups were similar with regard to demographic and surgical variables, but with a predominance of males in the ASD group 61.2% (p=.001). Rigid plates were used in 42% of all constructs and were more represented in the ASD(−) than ASD(+) group (48% vs. 33%, respectively, p=.017). The most common levels included in the fusion were C5-7 (28%). For all patients, preoperative lordosis was increased from 4.8p11.4° to 7.9p10.2° postoperatively and improved to 9.4p9.9° at final followup. Patients with greater kyphosis throughout the cervical spine at final followup had increased odds of developing ASD (OR 0.97 per degree, p=.040). Patients with greater preoperative kyphosis through the planned fusion segment had increased odds of ASD (OR 0.93 per degree, p=.003). Patients who lost lordosis through the fusion from initial postop to final followup had greater odds of developing ASD (OR 0.85 per degree, pl0.001). Patients who had greater change in preoperative to postoperative fusion segment lordosis were found to exhibit a greater risk of ASD (OR 1.06 per degree, p=0.019). The SVA and T1 slope angles did not change substantially from preoperative to postoperative and there were no differences between ASD groups. The mean postoperative and final proximal and distal segment lordosis was also not different between groups except for significantly less proximal adjacent segment lordosis in ASD patients at final follow-up (0.2p5.0 vs. 1.4p4.4; p=.026). There were no significant differences between preoperative, postoperative, or change in patient reported outcome surveys in patients with or without signs of radiographic ASD. CONCLUSIONS Patients with a greater preoperative cervical kyphosis and kyphosis through the proposed fusion segment may have greater odds of develeoping radiographic adjacent segment degeneration. Similarly, those that had a greater greater correction of cervical lordosis postoperatively, and those who loss lordosis at the fusion segment also presented with increased odds of developing adjacent segment degeneration. Our results suggest that preoperative and postoperative measures of cervical spine alignment, specifically related to C2-C7 and fusion segment lordosis, may predict the development of radiographic signs of adjacent level pathology following an ACDF.

Intradural extramedullary tumor in the stenotic cervical spine resected through open-door laminoplasty with hydroxyapatite spacers: report of two cases

BackgroundSafe excision of spinal cord tumors depends on sufficient visualization of the tumor and surrounding structures. In patients with spinal cord tumor adjacent to a stenotic spinal canal, extensive bony decompression proximal and distal to the tumor should be considered for safer excision of the tumor. Extensive wide laminectomy is one choice for such cases, but postoperative problems such as kyphotic deformity remain a concern.Case presentationA 76-year-old man and a 60-year-old woman presented with symptomatic intradural extramedullary spinal cord tumors in the cervical spine. Both patients showed a combination of spondylotic changes in the cervical spine and stenotic condition at the level of the tumor. Both tumors were successfully resected through open-door laminoplasty with hydroxyapatite (HA) spacers, with the tumor located on the side of the laminoplasty. Histological diagnosis was schwannoma for both tumors. HA spacers completely bonded to the host bone and did not interfere with postoperative magnetic resonance imaging (MRI) of the inside of the spinal canal. Cervical spine alignment was maintained at the final follow-up of 6 years in both cases.ConclusionLaminoplasty with HA spacers enabled successful tumor extirpation, reliable MRI follow-up after surgery, and maintenance of normal cervical spine alignment. Laminoplasty with HA spacers represents a good option for the treatment of cervical spinal cord tumor in patients combined with spinal stenosis.

Comparative Study for Cervical Spinal Fusion Using Cervical Cages with and Without Bone Granules

Abstract Background: Cervical spinal fusion is a surgical procedure that joins selected bones in the cervical spine.The anterior approach to the cervical spine was developed for treatment of cervical disc, it involves removing the symp-tomatic disc from an anterior approach without placement of a bone graft. Early studies demonstrated fusion rates with Anterior Cervical Discectomy (ACD) were similar to those of procedures of anterior cervical discectomy and fusion (ACDF) using bone graft. The anterior cervical discectomy and fusion with instru-mentation (ACDFI) technique involves the additional stabili-zation of the cervical spine & graft with instrumentation.Cages were introduced to be used with either autologous or synthetic bone grafts, promoting stability and encouraging fusion. Comparing to graft alternatives, cage interbody implants have better biomechanical properties, designed to maximise biocompatibility and reduced graft dislodgements, increased fusion rates, and decreased foraminal stenosis. However, placement of implants introduces hardware-related complica-tions.Aim of the Study: This prospective study aims to compare the results of ACDFI using cages with & without synthetic bone granules evaluating the outcomes, fusion and associated morbidities.Patients and Methods: Prospective study of 42 patients operated upon between 2012 and 2014 in Cairo University Hospitals & Beni Sueif University Hospital with ACDFI using cervical cages. Patients were divided into two groups: - Group (A) 22 patients operated by ACDFI with placement of cages only - Group (B) 20 patients operated by ACDFI with placement of cages and synthetic bone granules. Both groups underwent postoperative clinical follow-up for an average of 12 months, and results were evaluated according to radiographic evidence of fusion and Fisher exact probability test was used to compare fusion of both groups. We made considerations for patient's age, sex, osteoporosis, and smoking habits. We recorded fusion rates, cervical alignment, postoperative complications & patient satisfaction using Visual Analogue Score (VAS). Results: 42 patients were included in the study. The mean age was 46, 18 of them were females and 24 were males. 29 patients had single level discs and 13 patients had two levels.One year follow-up fusion rates that were achieved in group (A) were 81.8% while group (B) reached 95%. One year follow up on achievement of alignment of cervical spine was 90.9% of patient's in group (A) and in group (B) was 95% of cases.There were no problems regarding surgical technique or dislodgment in both techniques. Only in one patient in group(A)CSF leak developed and resolved. One patient in group(B)developed a keloid at incision site.Conclusion: Fusion rate is one of several factors that guide surgical decision making for cases requiring ACDFI. Fusion rate is significantly higher in group (B) using cages filled with synthetic bone granules than in group (A) with cages only. Age, sex, osteoporosis and smoking status have not given significantly different results between both groups studied.

Normal sagittal profile of the cervical spine- must the cervical spine always be lordotic?

The cervical spine is very complex, and it allows the largest range of motion relative to the rest of the spine. The fundamental function of the cervical spine is to maintain the head balanced over the trunk and to maintain horizontal gaze. The cervical spine must be both stable and flexible to guarantee function. Changes of the sagittal profile of the cervical spine may affect function and quality of life. The relationship between full body alignment and maintaining gaze necessitates athorough understanding of the cranio-spino-pelvic alignment as acomponent of balance. Now the question is, what kind of sagittal profile does the cervical spine need for proper function? In the literature, normal sagittal alignment of the cervical spine is controversial. In general, there is the assumption that the alignment is lordotic. Does the data in the literature support this? The present literature review supports the following facts: Ideal cervical spine alignment is mostly lordotic, but not always; ideal cervical spine alignment can be lordotic, neutral or kyphotic; ideal cervical spine alignment is driven by the necessity of supporting the head and maintaining horizontal gaze; the cervical spine is in harmony with regional alignment (thoracic kyphosis) and sagittal global alignment (SVA): TK(↑) → T1Slope(↑) → CL(↑), TK(↓) → T1Slope(↓) → CL(↓), SVA >50 mm: the cervical curve should be lordotic to maintain horizontal gaze, SVA <0 mm: the cervical curve should be kyphotic to maintain horizontal gaze.

Characteristics of Cervical Spine Motion in Different Types of Cervical Alignment: Kinematic MRI Study.

Retrospective study. To evaluate how each type of sagittal cervical alignment affects the motion of the upper and subaxial cervical spine using kinematic magnetic resonance imaging. The sagittal malalignment of the cervical spine from degeneration in the subaxial cervical spine reflects a disruption in the kinematic properties of the cervical spine and affects the motion of adjacent segments. Changes in the sagittal parameters and kinematics of the upper cervical spine and upper thoracic spine due to the kyphosis are unknown. Kinematic magnetic resonance imaging of the cervical spine in neutral position from 311 patients, including 90 lordotic, 90 straight, 90 global kyphotic, and 41 segmental kyphotic were analyzed. The lordotic angle at the upper and lower cervical spine, and T1 slope were measured in the neutral position and again in flexion and extension for dynamic analysis. The number of levels with significant disk degeneration was higher in the global kyphosis group. In the global kyphosis group, neutral sagittal parameters showed some characteristics of compensation to the malalignment. Compared with the lordotic group, patients with global kyphosis demonstrated significantly higher lordotic angle of the upper cervical spine and more horizontal T1 slope. The dynamic evaluation showed greater range of motion of the entire cervical spine and subaxial cervical spine in younger patients. However, we still found greater range of motion of the occipito-atlanto-axial complex in global kyphosis, even when controlling for age and number of levels with significant disk degeneration. Sagittal malalignment of the cervical spine affects all parts of the cervical motion complex. The global kyphotic alignment of subaxial cervical spine affects the kinematic properties of the occipito-atlanto-axial complex and upper thoracic spine to compensate for the alteration of cervical alignment. These differences are not seen in straight and segmental kyphosis. Level 3.

Clinical and radiological outcomes of cervical disc arthroplasty: tenyear follow-up study.

Previous studies have demonstrated that cervical disc arthroplasty has favourable short- and medium-term clinical and radiological outcomes. However, long-term follow-up outcomes have rarely been reported. The purpose of this study was to evaluate the tenyear follow-up clinical and radiological outcomes in patients who underwent Bryan cervical disc arthroplasty. Seventy-one patients who underwent single-level Bryan cervical disc arthroplasty with a minimum tenyear follow-up were included in the study. Japanese Orthopaedic Association (JOA) score, neck disability index (NDI), and Odom's criteria were used to evaluate clinical outcomes. X-ray, CT, and MRI were used to evaluate the radiological outcomes. At last follow-up, the JOA score and NDI improved significantly, and 65 patients (91.5%) had good or excellent outcomes according to Odom's criteria. The range of motion (ROM) at operated level was 9.7° pre-operatively and maintained to 8.6° at last follow-up. The sagittal alignment of operated level was decreased from 2.1° pre-operatively to 1.2° at last follow-up (P < 0.01). The ROM and sagittal alignment of cervical spine had no significant change. At last follow-up, 16 patients (22.5%) developed segmental kyphosis, and 33 patients (46.5%) developed adjacent segment degeneration. Paravertebral ossification (PO) was observed in 66 patients (93.0%), and high-grade PO (grades III and IV) was observed in 25 patients (35.2%). The clinical and radiological outcomes of Bryan cervical disc arthroplasty over tenyears follow-up are satisfying. However, the occurrence of high-grade PO restricted the ROM of operated level.

Growth and alignment of the pediatric subaxial cervical spine following rigid instrumentation and fusion: a multicenter study of the Pediatric Craniocervical Society.

OBJECTIVE The long-term effects of surgical fusion on the growing subaxial cervical spine are largely unknown. Recent cross-sectional studies have demonstrated that there is continued growth of the cervical spine through the teenage years. The purpose of this multicenter study was to determine the effects of rigid instrumentation and fusion on the growing subaxial cervical spine by investigating vertical growth, cervical alignment, cervical curvature, and adjacent-segment instability over time. METHODS A total of 15 centers participated in this multi-institutional retrospective study. Cases involving children less than 16 years of age who underwent rigid instrumentation and fusion of the subaxial cervical spine (C-2 and T-1 inclusive) with at least 1 year of clinical and radiographic follow-up were investigated. Charts were reviewed for clinical data. Postoperative and most recent radiographs, CT, and MR images were used to measure vertical growth and assess alignment and stability. RESULTS Eighty-one patients were included in the study, with a mean follow-up of 33 months. Ninety-five percent of patients had complete clinical resolution or significant improvement in symptoms. Postoperative cervical kyphosis was seen in only 4 patients (5%), and none developed a swan-neck deformity, unintended adjacent-level fusion, or instability. Of patients with at least 2 years of follow-up, 62% demonstrated growth across the fusion construct. On average, vertical growth was 79% (4-level constructs), 83% (3-level constructs), or 100% (2-level constructs) of expected growth. When comparing the group with continued vertical growth to the one without growth, there were no statistically significant differences in terms of age, sex, underlying etiology, surgical approach, or number of levels fused. CONCLUSIONS Continued vertical growth of the subaxial spine occurs in nearly two-thirds of children after rigid instrumentation and fusion of the subaxial spine. Failure of continued vertical growth is not associated with the patient's age, sex, underlying etiology, number of levels fused, or surgical approach. Further studies are needed to understand this dichotomy and determine the long-term biomechanical effects of surgery on the growing pediatric cervical spine.

Dynamic Cervical Radiographs in Patients with Hirayama Disease: An Unneglectable Factor on the Choice of Surgery Options.

To evaluate the cervical spine alignment and range of motion (ROM) of neck flexion in patients with Hirayama disease. Fifty male patients were included, with dynamic radiographs and magnetic resonance imaging (MRI) analyzed retrospectively. The Cobb angles for the entire cervical spine (C2-C7) and each level (C2/3-C6/7) were measured, and the neck flexion ROM was defined as the neutral Cobb angle minus the flexion Cobb angle. Paired t tests and Wilcoxon signed-rank tests were used to compare the Cobb angles and ROM between radiographs and MRI. The neutral and flexion Cobb angles decreased from C2/3 to C5/6 but increased at C6/7 on radiographs and MRI. The neutral Cobb angle of C2-C7 from radiographs was significantly larger than that seen on MRI (5.27° vs.-3.26°; P < 0.0001). Neck flexion ROM seen with MRI tended to be lower than those of corresponding levels on radiographs. The ROM of C2-C7, C3/4, and C6/7 on radiographs was significantly larger than that seen with MRI (37.86° vs. 26.59°, P < 0.0001; 7.46° vs. 5.10°, P= 0.0071; and 10.45° vs. 7.03°, P= 0.0023, respectively). For the lower cervical levels, the largest and second largest ROM were seen in C5/6 and C6/7 on the radiographs but C5/6 and C4/5 on MRI. The cervical spine alignment and neck flexion ROM in Hirayama disease differed between radiographs and MRI. Both imaging techniques should be examined comprehensively when planning an operation.

The Reliabilities of Several Measurement Methods of Cervical Sagittal Alignment in Cases with Cervical Spine Rotation Using X-ray Findings in Cervical Spine Disorders.

Introduction Several measurement methods designed to provide an understanding of cervical sagittal alignment have been reported, but few studies have compared the reliabilities of these measurement methods. The purpose of the present study was to investigate the intraexaminer and interexaminer reliabilities of several cervical sagittal alignment measurement methods and of the rotated cervical spine using plain lateral cervical spine X-rays of patients with cervical spine disorders. Methods Five different measurement methods (Borden's method; Ishihara index method (Ishihara method); C2-7 Cobb method (C2-7 Cobb); posterior tangent method: absolute rotation angle C2-7 (ARA); and classification of cervical spine alignment (CCSA)) were applied by seven examiners to plain lateral cervical spine X-rays of 20 patients (10 randomly extracted cases from a rotated cervical spine group and 10 from a nonrotated group) with cervical spine disorders. Case 1 and Case 2 intraclass correlation coefficients (ICCs) were used to analyze intraexaminer and interexaminer reliabilities. The necessary number of measurements and the necessary number of examiners were also determined. The target coefficient of correlation was set at ≥0.81 (almost perfect ICC). Results In both groups, an ICC(1, 1) ≥ 0.81 was obtained with Borden's method, the Ishihara method, C2-7 Cobb, and ARA by all examiners. The necessary number of measurements was 1. With CCSA, a kappa coefficient of at least 0.9 was obtained. In both groups, with Borden's method, the Ishihara method, C2-7 Cobb, and ARA, the ICC(2, 1) was ≥0.9, indicating that the necessary number of examiners was 1. The standard error of measurement (SEM) was lowest with Borden's method, and the Ishihara method and C2-7 Cobb had almost the same values. Conclusions Among cervical sagittal alignment measurement methods for cervical spine disorders, regardless of cervical spine rotation, Borden's method, Ishihara method, and C2-7 Cobb offer stronger reliability in terms of the ICC and SEM.

Long-term follow-up of C(1)-C(2) pedicle screw fixation for pediatric atlantoaxial dislocation

Objective: To investigate the clinical curative effect of C(1)-C(2) pedicle screw fixation for pediatric atlantoaxial dislocation after a long-term follow-up. Methods: From March 2005 to April 2011, a total of 12 male and 9 female patients were included, with age from 3 to 9 years old (mean, 6.1 years old). Among them, 14 cases (67%) had typeⅠinstability atlantoaxial dislocation, 7 cases (33%) had type Ⅱ reducible atlantoaxial dislocation. All 21 pediatric patients with atlantoaxial dislocation underwent posterior pedicle screw fixations. Frankel Grade was used to evaluate function before and after treatment. Furthermore, the information of C(1)-C(2) bony fusion, cervical spine alignment, angle of sagittal curvature, and instability of the subaxial spine were collected from all patients preoperatively, immediately postoperatively and during follow-up period. Results: All 21 patients had regular follow-up with an average duration of 96.4 months (range, 65 to 127 months). All children had good bony fusion within 6 months after treatment. There were 9 patients with lordotic alignment and 12 patients with straight alignment before surgery. After surgery, there were 12 patients with lordotic alignment and 9 patients with straight alignment. At the time of the last follow-up, 17 patients had lordotic alignment and 4 patients had straight alignment. No difference was found between pre- and post-operation (P=0.354). The same result was found between post-operation and last follow-up (P=0.095). Neither kyphotic nor swan-neck deformity was found in any of the 21 patients. The mean angle of sagittal curvature decreased from 31.7°±4.3°preoperatively to 15.5°±2.5°postoperatively (P<0.001). The mean angle of sagittal curvature increased from 15.5°±2.5°postoperatively to 19.1°±2.7°at the final follow-up (P=0.343). No spinal deformities or subaxial instabilities were found. Of the four patients with preoperative neurological defects, Frankel Grade was significantly improved at 3 months follow-up compared with pretreatment values. None of the patients experienced worsening neurological symptoms or injury to the vertebral artery. Conclusion: The results demonstrate that C(1)-C(2) pedicle screw fixation could achieve satisfactory clinical effects for the management of pediatric atlantoaxial dislocation with long-term follow-up.

Risk factors for non-fusion segment disease after anterior cervical spondylosis surgery: a retrospective study with long-term follow-up of 171 patients

BackgroundThe purpose of this study was to investigate the incidence and causes of non-fusion segment disease (NFSD), both adjacent and non-adjacent to a fused segment, after anterior cervical arthrodesis.MethodsThis is a single-center study. Between January 1998 and January 2011, two surgeons’ 171 patients who had an anterior cervical decompression and fusion were followed clinically for more than 5 years. The correlation between the incidence of symptomatic non-fusion segment disease and the following clinical parameters (age at operation, fusion levels,) and radiological parameters (number of patients who had a plate, anterior cervical decompression and fusion (ACDF) or corpectomies, preoperative and postoperative cervical spine alignment, Pavlov’s ratio at the C5 level, and preoperative existence of a non-fusion segment degeneration on magnetic resonance imaging) was evaluated.ResultsOf the 171 patients reviewed, 16 patients had non-fusion segment disease (9.36%), of which 12 had adjacent segment disease and 4 had non-adjacent segment disease. Postoperative cervical lordosis in the non-fusion segment disease group was significantly smaller than that of the disease-free group (P < 0.001). Fusion levels in the NFSD group were 1.69 whereas 2.26 in disease-free group (P = 0.005). The incidences of disc degeneration in unfused segments was more severe in the NFSD group than in the disease-free group (P = 0.004). The results of binary logistic regression showed that the major factor affecting NFSD is postoperative cervical lordosis (P = 0.000) followed by disc degeneration (P = 0.024). The other parameters did not show a statistically significant difference.ConclusionsThe incidence of symptomatic non-fusion segment disease after anterior cervical arthrodesis has multifactorial causes. Postoperative cervical lordosis and disc degeneration in non-fusion segments were major factors in the incidence of NFSD.

Cervical Laminectomy with Lateral Mass Screw Fixation in Cervical Spondylotic Myelopathy: Neurological and Sagittal Alignment Outcome: Do We Need Lateral Mass Screws at each Segment?

Background:Anterior cervical decompression and fusion is the standard procedure used for treating patients with cervical myelopathy. However, these procedures are associated with complications such as pseudarthrosis, construct failure, and neurological complications. Posterior cervical laminectomy and instrumentation is an alternative procedure to treat multilevel cervical myelopathy. In this study, we raised questions whether instrumentation is required at all levels and whether stabilizing the spine in neutral or lordotic contour with indirect decompression leads to neurological improvement with radiological evidence of anterior decompression. The results of posterior cervical laminectomy and instrumentation with lateral mass screw in terms of radiological and functional outcome in patients with multilevel cervical myelopathy are prospectively evaluated.Materials and Methods:In this prospective study conducted between June 2006 and December 2015, we have evaluated 112 patients with multilevel cervical myelopathy who underwent multilevel cervical laminectomy and instrumentation with lateral mass screw. All patients were evaluated preoperatively and postoperatively with Nurick's grading and Modified Japanese Orthopaedic Association (mJOA) scale for neurological function. Cooper scale and British Medical Research Council grading system for motor function. Curvature index was used to measure the alignment of cervical spine preoperatively and postoperatively. Alignment of the cervical spine was done preoperatively and postoperatively by calculating the curvature index. Axial MRI was used to calculate the severity of compression preoperatively which was calculated as per Singh's criteria and postoperatively to assess the adequacy of decompression at the operated level.Results:In our study, there were 112 patients including 99 males and 13 females, with mean age of 59.53 years. The mean duration of followup of patients was 33.24 months. In total, cervical laminectomy was performed at 342 levels in 112 patients with an average of 3.05 laminectomies, and in total, 112 lateral mass screws were inserted. On postoperative followup, the mJOA and Nurick's grading showed improvement in all cases as compared to preoperative findings. The mean mJOA improved significantly from 8.56 preoperatively to 13.57 postoperatively (P < 0.001). The mean Nurick's grading also improved significantly from 2.59 preoperatively to 0.66 postoperatively (P < 0.001). The mean Cooper scale also showed significant improvement in both upper and lower limbs postoperatively (P < 0.001). The mean preoperative Cooper scale was 1.75 and postoperative was 0.31 for upper limbs, and the mean Cooper scale was 2.14 preoperatively and 0.56 postoperatively for lower limbs. X-rays done on routine followups showed good alignment of the cervical spine with maintenance of curvature index in all patients. The mean grade of compression as seen on preoperative MRI was 2.46 which reduced significantly postoperatively to 0.16 (P < 0.001).Conclusion:The multilevel cervical laminectomy and instrumentation with lateral mass screw for multilevel cervical myelopathy is a safe technique that provides decompression of the spinal cord, prevents the development of kyphotic spinal deformity and posterior tension band of the spinal cord as associated with laminoplasty or uninstrumented laminectomy.

Closed reduction of traumatic atlantoaxial rotatory subluxation with type II odontoid fracture

Abstract Background Traumatic atlantoaxial rotatory subluxation (TAARS) in adults is rare. We present an uncommon case of traumatic atlantoaxial rotatory subluxation with an associated type II odontoid fracture in a neurologically intact patient and describe a novel technique used for a successful closed reduction. Case description A 20-year-old female presented with a decreased level of consciousness after being involved in a motor vehicle accident at highway speeds. A computed tomography (CT) demonstrated atlantoaxial rotatory subluxation and a type II odontoid fracture. CT angiography showed a left V3 vertebral dissection. She was neurologically intact on examination. A halo ring was applied and the patient successfully underwent closed reduction using traction and a novel transoral reduction technique described below. After closed reduction, a C1–C2 posterior instrumented fusion was performed. At 12-weeks follow-up, the patient was asymptomatic, neurologically intact with optimally maintained cervical spine alignment. Conclusion Prompt manual closed reduction can safely be achieved in adults using this novel transoral reduction technique, which we describe for the first time in this report.

Cage with anterior plating is advantageous over the stand-alone cage for segmental lordosis in the treatment of two-level cervical degenerative spondylopathy: A retrospective study

ObjectivesTo compare retrospectively the clinical and radiological outcomes in cervical spinal alignment after two consecutive levels PEEK cage-assisted ACDF when performed with or without plate fixation Patients and methodsSeventy-eight patients underwent two consecutive levels PEEK cage-assisted ACDF without plating (56 patients) or supplemented with plating (22 patients). The average clinical follow-up was 31.40±12.98months. The authors compared clinical parameters (Neck disability index and Robinson criteria), perioperative parameters (hospital stays, complications), and radiological parameters (global lordotic curvature, segmental lordosis, segmental height). ResultsDemographic features, neurological presentation, preoperative sagittal alignment, postoperative complications, length of hospitalization and clinical improvement were not different between groups. At 12-months radiological follow-up, the global lordotic curvature was similar in both groups (P=0.02). However, the use of anterior plate fixation versus stand-alone cage was associated with greater segmental lordosis (−7.68±4.82° versus −0.02±8.44°, P<0.0001) and greater segmental height (39.51±3.50 versus 36.75±3.90, P=0.005). ConclusionThe clinical outcomes after two consecutive levels PEEK cage-assisted ACDF with and without plate fixation were similar, but the supplement of an anterior plate was advantageous for improving segmental alignment on long-term radiological follow-up.

Cervical Laminoplasty: A Review of Indications, Technique and Outcomes

Laminoplasty is a motion-sparing decompression technique for the cervical spine. As the first description was published over 40 years ago, it has been established as an effective treatment for cervical spondylotic myelopathy. The application of this technique is predicated on maintenance of physiologic sagittal alignment in the cervical spine. Numerous variations of the originally published laminoplasty technique exist and they can be broadly categorized into symmetric or asymmetric canal expansions. Potential complications include chronic neck pain, C5 palsy, and door closure, among others. Recent clinical research suggests sparing the muscle attachments on the C2 and C7 spinous process may improve the incidence of pain. The purpose of this article is to review the indications and contraindications for cervical laminoplasty and evaluate its efficacy based on current literature.

Analysis of cervical spine alignment in currently asymptomatic individuals: prevalence of kyphotic posture and its relationship with other spinopelvic parameters

Background contextMany studies tend to characterize cervical kyphosis as a significant clinical condition that needs to be treated. Moreover, opinions vary on whether cervical kyphosis should be considered a pathologic status or a natural occurrence in asymptomatic people. PurposeThis study aimed to determine the frequency of kyphotic posture of the cervical spine in currently asymptomatic individuals and to ascertain its relation with other spinopelvic parameters. Study DesignA cross-sectional radiographic study was carried out. Patient SampleThis study targeted 1,026 currently asymptomatic adult volunteers who agreed to participate in this study from January 2010 to March 2016. Only 958 were eligible for the study. Outcome MeasuresRadiographic images, including the C-spine dynamic view and whole-spine lateral view, were measured. The sagittal parameters of the cervical spine and other parts of the spine and pelvis, such as the C2–C7 angle, C0–C2 range of motion (ROM), C2–C7 ROM, and C0–C7 ROM, thoracic kyphosis, lumbar lordosis, sacral slope, pelvic tilt, and pelvic incidence, were measured. MethodsBased on the C-spine neutral lateral X-ray, a C2–C7 Cobb angle greater than 0 degree was defined as lordosis and an angle less than 0 degree was defined as kyphosis. Patients who showed kyphosis were further classified into the reducible or non-reducible group, depending on the ability of recovering neck motions (lordosis) in extension. The cervical and other global spine parameters between the two groups were analyzed, and the relation between the cervical alignment and other parts of the spine and pelvis were also examined. This study was not supported by any funding and had no conflicts of interest. ResultsNearly one-fourth of the asymptomatic participants (26.3%) have kyphotic cervical posture, and almost one-sixth of the kyphotic individuals (16.7%) have non-reducible kyphosis. The prevalence increases with advanced age; non-reducible cases are mostly kyphotic, kyphosis stems from the C2–C7 region, and kyphosis is not correlated with any of the radiological parameters of the other parts of the spine except lumbar lordosis. ConclusionsCervical kyphosis can be observed in normal healthy adults.

Comparaison entre la décompression antérieure et postérieure de la moelle lors du traitement chirurgical de la myélopathie cervicarthrosique. Résultats d’une étude prospective non randomisée

IntroductionThe laminoplasty has been the most widely used surgical method for OPLL. In recent years, increasing attention has been drawn to the anterior operative approaches for surgical treatment of cervical OPLL. However, which method is the optimum selection for therapy of cervical OPLL is still obscure. Therefore, we performed this prospective nonrandomized clinical study in patients with multi-level cervical myelopathy due to OPLL and compare the therapeutic efficiency of laminoplasty and anterior approach (cervical discectomy and/or cervical corpectomy) in the management of multi-level cervical OPLL. HypothesisThere is no difference in clinical effects between anterior cervical spine surgery and laminoplasty in treatment of multi-level cervical OPLL. Material and methodsA total of 150 consecutive patients with multi-levels of cervical OPLL underwent anterior approaches (ACDF, ACCF and HDF) from July 2010 to June 2014, which were enrolled in this study. During the same period, one hundred and two patients receiving the laminoplasty were enrolled in the study. The clinical effects, alignment and range of motion (ROM) of cervical spine in patients of the anterior group and posterior group were assessed, respectively. The effects of high signals in T2 weighed MRI scans and percentage of spinal canal stenosis in these patients were also evaluated. Finally, postoperative complications regarding each group were analyzed. ResultsAlthough significant differences in types of OPLL and preoperative sagittal alignment of cervical spine occurred in the two groups (P<0.05), clinical effects of the two groups were similar (P>0.05). The cervical curvature in laminoplasty group showed significant decrease at final follow-up (P<0.05). For ROM of cervical spine, no significant alteration was observed in both groups. The high T2 weighed signals and rate of spinal canal stenosis can influence clinical effects of both anterior group and laminoplasty group. In addition, significantly higher complication rate was observed in laminoplasty group compared with anterior group (P<0.05). DiscussionBoth anterior and laminoplasty approaches can be considered effective and safe procedures in the treatment of the multi-level OPLL. However, the anterior approach with relatively lower incidence of postoperative complications is a better choice for cases with poor cervical curvature and serious spinal canal stenosis. Type of study and level of proofLevel 3 nonrandomized, controlled clinical trials.

The Assessment of Upright Cervical Spinal Alignment Using Supine MRI Studies.

This is a prospective, single-centre study. The purpose of this study is researching whether there is a correlation or not between the cervical alignment in the examinations of magnetic resonance imaging (MRI) in lying position and the alignment in the cervical direct radiography and whether the cervical alignment in standing position could be estimated or not through MRI measurements in the supine position. Cervical spinal alignment is a parameter required for deciding the surgical procedure particularly in patients with cervical myelopathy and deformity. However, cervical alignment angles change according to lying and standing positions. Therefore, the direct standing radiograph is taken as basis for this examination. Cervical alignments were measured with 3 different methods with the standing lateral radiographies and lying MRI of 51 patients with cervical disorder. A high correlation was found between the measurements in standing and lying positions for the spinal alignments measured through the Cobb angle and posterior tangent method. It was found that standing Cobb angle (in plain graphy)=Cobb angle (in MRI)×0.489+7.13 and posterior tangent angle (in plain graphy)=posterior tangent angle (in MRI)×0.54+9.37. It is possible to estimate the spinal alignment in standing position with the measurements of cervical spinal alignment in the MRI at supine position. And this may render having cervical graphy in standing position unnecessary.

Usefulness of anterior cervical fusion using titanium interbody cage for treatment of cervical degenerative disease with preoperative segmental kyphosis

Favorable bone fusion and clinical results have been reported for anterior cervical fusion (ACF) using titanium interbody cage (TIC). This method might induce postoperative subsidence and local kyphosis, but the relationship between radiological changes and preoperative local alignment is not known. The purpose of the present study is to investigate the impact of preoperative local alignment on the clinical and radiological outcomes of ACF using TIC.The study enrolled 36 patients (mean age 49.8 years) who underwent single-level ACF using TIC for cervical degenerative diseases. Patients were divided into 2 groups by preoperative segmental lordotic angle at the operative level: group L, ≥0° (n = 16); group K, <0° (n = 20). Clinical outcomes included recovery rate according to the Japanese Orthopaedic Association score and complication rates. Radiological assessment was conducted for the cervical and segmental lordotic angles, subsidence, and bone fusion. Mann–Whitney test and chi-square test were applied to compare the outcomes.The Japanese Orthopaedic Association score recovery rate was 77.2% in group L and 87.6% in group K, with no significant difference. No obvious complications were observed in any of the subjects. Mean cervical lordotic angles preoperatively and at last follow-up were 9.2 ± 9.5° and 11.3 ± 11.7°, respectively, in group L, and −1.3 ± 12.8° and 4.6 ± 13.3°, respectively, in group K. The mean segmental lordotic angles preoperatively and at last follow-up were 2.5 ± 2.2° and 2.6 ± 5.7°, respectively, in group L, and −4.5 ± 2.8° and −1.4 ± 5.8°, respectively, in group K. In group K, the cervical and segmental lordotic angles at the last follow-up were significantly greater than the preoperative angles. The change observed in group L was not significant. Subsidence of ≥3 mm was observed in 3 patients in group L and 4 patients in group K. None of the patients showed nonunion.Anterior cervical fusion using TIC provided favorable clinical results regardless of preoperative segmental alignment. Although postoperative subsidence and kyphotic changes are concerns in patients presenting segmental kyphosis, ACF using TIC corrected both the entire cervical spine and segmental alignment. The TIC is useful for correction of the cervical alignment for patients with cervical degenerative disease with local kyphotic changes.

The change of cervical spine alignment along with aging in asymptomatic population: a preliminary analysis

A cross-sectional study. To investigate the correlation of cervical spine alignment changes with aging in asymptomatic population. Previous studies demonstrated the influence of lumbar and thoracic spine on cervical spine alignment, but few has reported the cervical spine alignment change along with aging in asymptomatic population. Asymptomatic population were divided into four groups according to different ages (Group A: ≤20years; Group B: 21-40years; Group C: 41-60years; Group D: ≥61years). Each group was composed of 30 subjects. The following parameters were measured: C0-1 Cobb angle, C1-2 Cobb angle, C2-7 Cobb angle, C1-7 sagittal vertical axis (C1-7 SVA), C2-7 SVA, central of gravity to C7 sagittal vertical axis (CG-C7 SVA), Thoracic Inlet Angle (TIA), Neck Tilt (NT), cervical tilt, cranial tilt, T1 slope (TS), TS-CL, and ANOVA statistical method was used to analyze the differences among four groups, and then, linear regression analysis was performed to analyze correlation of the cervical spine alignment with the aging. C1-7 SVA, C2-7 SVA, CG-C7 SVA, TIA, NT, TS, and cranial tilt were found statistically different among four groups (P<0.01). From Group A to Group D, the mean C1-7 SVA were 30.7, 26.0, 21.8, and 36.9mm, the mean C2-7 SVA were 18.7, 14.7, 11.9, and 24.7mm, and the mean CG-C7 SVA were 19.6, 16.6, 9.4, and 26.7mm. The mean TIA were 62.4°, 65.0°, 71.8°, and 76.9°, the mean NT were 39.4°, 43.8°, 46.3°, and 48.2°, the mean TS were 23.0°, 21.1°, 25.5°, and 28.7°, and the mean cranial tilt were 5.7°, 4.8°, 3.0°, and 9.5°. Further linear regression indicated that TIA (r=0.472; P<0.0001), NT (r=0.337; P=0.0006), and TS (r=0.299; P=0.0025) were positively correlated with aging. A gradual increase of TIA, NT, and TS, accompanied with an increased CL, is found along with aging in asymptomatic population, among which TIA, NT, and TS are significantly correlated with physiological nature of aging.